A roller conveyor is known from DE 41 26 822 A1 which serves to convey work pieces, or work pieces or skids fastened to work piece supports to a processing station. The roller conveyor has longitudinal supports running adjacent and parallel to one another, by means of which and between which a plurality of supporting rollers is rotatably mounted.
In one of the embodiments shown, each supporting roller has a tubular hub rotatably mounted on the shaft member by means of ball bearings and having an external tooth arrangement. The hub is made of light metal and bears two attached flanged pulleys containing a corresponding internal tooth arrangement in order to create a rotationally fixed connection with the hub. A tubular polyurethane covering, which on the surface of its internal periphery also contains an internal tooth arrangement corresponding to the hub, sits between the flanged pulleys. The assembly is secured in axial direction by retaining rings.
The covering of the supporting rollers is subject to wear since the work pieces and work piece supports transported with such roller conveyors in actual fact have a weight of up to four tons, which means that forces of up to half a ton act on the driving elements. Correspondingly high lateral guiding forces must be applied by the flanged pulley which has the task of laterally guiding the work piece support.
Considerable wear occurs on the covering and the flanged pulleys as a result of the operating conditions.
Moreover, because of the relatively narrow face with which they lie on the hub, high forces occur at the hole of the flanged pulley if the work piece support runs against the flanged pulley. This also has a detrimental effect on the period of service of the flanged pulley and thus on the entire supporting roller.
Moreover, production is expensive because of the many individual parts from which the supporting roller is assembled.
A further embodiment for a conveyor roller is shown in EP 0 009 508 A1. In this conveyor roller, the support section, the flanged pulley and the driving section are integrally connected to one another. The unit thus formed sits rotationally fixed on a shaft member, i.e. without a tooth arrangement, as shown in the figure. This means a press-fit connection with the shaft member, which is, however, only durable if both the shaft member and the roller are made of metal. There is no covering.
A support roller for conveyor belts is described in DE-GM 86 34 166. This support roller comprises a hub and a covering fastened to the surface of the outer periphery of the hub. The hub itself is an injection moulded part made of a thermoplastic plastic, onto which the covering or shell is injected.
The connection between the hub and the shell, which is made of rubber, is positive because of the corresponding structure of the outer contour of the hub.
The support roller is not provided to be actively driven.